Current Approach in Radiochemical Quality Control of the 99mTc-Radiopharmaceuticals: a mini-review

Abstract To present optimized chromatographic systems for radiochemical purity (RCP) evaluation of 99mTc-eluate and 99mTc-radiopharmaceuticals, as well as to assess doses calibrator reliability for routine purposes in hospital radiopharmacies. RCP was determined by different systems and radioactivity was quantified by TLC-scanner, doses calibrator and gamma-counter. Suitable and optimized systems were presented for RCP analyses. No significant differences were observed between radioactivity counting devices and, thus, doses calibrator showed reliability for RCP determination in hospital radiopharmacies.

Preparation, quality control and thyroid molecule imaging of solid-target based radionuclide ioine-124 / 北京大学学报(医学版)

OBJECTIVE@#To provide useful information for the further production and application of this novel radio-nuclide for potential clinical application.@*METHODS@#124Te (p,n) 124I nuclide reaction was used for the 124I production. Firstly, the target material, 124TeO2 (200 mg) and Al2O3 (30 mg) mixture, were compressed into the round platinum based solid target by tablet device. HM-20 medical cyclotron was applied to irradiate the solid target slice for 6-10 h with helium and water cooling. Then, the radiated solid target was placed for 12 h (overnight) to decay the radioactive impurity; finally, 124I was be purified by dry distillation using 1 mL/min nitrogen for about 6 hours and radiochemical separation methods. Micro-PET imaging studies were performed to investigate the metabolism properties and thyroid imaging ability of 124I.After 740 kBq 124I was injected intravenously into the tail vein of the normal mice, the animals were imaged with micro-PET and infused with CT. The micro-PET/CT infusion imaging revealed actual state 124I's metabolism in the mice.@*RESULTS@#It was been successfully applied for 200 mg 124TeO2 plating by the tablet device on the surface of platinum. It showed smooth, dense surface and without obviously pits and cracks. The enriched 124Te target was irradiated for 6 to 10 hours at about 12.0 MeV with 20 μA current on HM-20 cyclotron. Then 370-1 110 MBq 124I could be produced on the solid target after irradiation and 370-740 MBq high specific activity could be collected afterdry distillation separation and radio-chemical purification.124I product was finally dissolved in 0.01 mol/L NaOH for the future distribution. The gamma spectrum of the produced 124I-solution showed that radionuclide purity was over 80.0%. The micro-PET imaging of 124I in the normal mice exhibited the thyroid and stomach accumulations and kidney metabolism, the bladder could also be clearly visible, which was in accordance with what was previously reported. To the best of our knowledge, it was the first production of 124I report in China.@*CONCLUSION@#In this study, the preparation of 124TeO2 solid target was successfully carried out by using the tablet device. After irradiation of the 124TeO2 solid target and radio-chemical purification, we successfully produced 370-740 MBq high specific activity 124I by a cyclotron for biomedical application, and micro-PET imaging of 124I in normal mice exhibited the thyroid accumulations. Also, slight uptake in stomach were also monitored with almost nonuptake in other organs in the micro-PET imaging. The production of 124I is expected to provide a new solid target radionuclide for the scientific research and potential clinical application of our country.

Obligations, precautions and pending issues in regulatory development for radiopharmaceuticals in Brazil

Radiopharmaceuticals are compounds that have a radionuclide and may be gamma-radiation emitter (γ) or positrons emitter (β+), linked to a molecule with specific diagnostic and therapeutic purposes. The progress in the use of radiopharmaceuticals has culminated to a sector in common with other types of drugs: regulation and surveillance. From 2006 on, production, marketing and use of these drugs were open to the Brazilian market granting much more freedom due to the Constitutional Amendment 49, resulting from the previous Constitutional Amendment 199/03 which removes the Union monopoly for this kind of manipulation and granted this production to other nuclear medicine. From this date on, the amount of this type of sold product have been greatly increased, and the nucleus of surveillance and regulation in Brazil have also advanced in the legislative processes, creating documents that are now more focused on radiopharmaceuticals in the national territory (Resolutions No. 63 and No. 64). In international overview, there is too much to be done in regulatory terms in Brazil, such as adding mainly issues of drugs surveillance to pharmacovigilance practice in radiopharmaceuticals drugs.

Radiofármacos são compostos que possuem um radionucleotídeo, podendo ser emissor de radiação gama (γ) ou emissor de pósitrons (β+), ligado a uma molécula específica com finalidade diagnóstica e terapêutica. O avanço no uso dos radiofármacos tem culminado a um setor em comum com outros tipos de medicamentos: a regulamentação e fiscalização. Após 2006, a produção, a comercialização e a utilização destes medicamentos foram abertas ao mercado interno brasileiro com maior liberdade, pois a Emenda Constitucional 49, vinda da Emenda Constitucional 199/03, que retira da União o monopólio deste tipo de manipulação, ofereceu a outros centros de medicina nuclear a oportunidade desta produção. A partir desta data, a quantidade comercializada deste tipo de medicamento aumentou absurdamente e os núcleos de vigilância e regulamentação do Brasil avançaram também nos processos legislativos, criando os documentos mais voltados a Radiofármacos existentes no território nacional, as Resoluções n° 63 e n° 64. Em visão internacional, há muito ainda a ser feito em termos regulatórios no Brasil somando principalmente os assuntos vigilantes dos medicamentos como a prática de Farmacovigilância em Radiofármacos.

Fatores de correção volumétrica na medição de atividade de 99mTc e 123I em calibradores de radionuclídeos / Volume corrections factors in the measurement of 99mTc and 123I activities in radionuclide calibrators

OBJETIVO: Determinar os fatores de correção para a variação volumétrica dos radiofármacos contidos em recipientes de diferentes geometrias. Comparar a influência desses fatores na determinação da atividade de 99mTc e 123I utilizando dois tipos de calibradores: um com câmara de ionização e outro com detector Geiger-Müller (G-M). Avaliar o desempenho de calibradores de alguns serviços de medicina nuclear em medição de atividade de 99mTc e 123I. MATERIAIS E MÉTODOS: Foram utilizados oito calibradores, frascos de vidro 10R, seringas de plástico de 3 e 5 mL e soluções de 99mTc e 123I. Os fatores de correção foram determinados a partir das medições práticas da variação da leitura do calibrador com a variação do volume da solução no recipiente. O desempenho foi avaliado em relação ao critério de aceitação de ±10% de exatidão exigida pela norma brasileira. RESULTADOS: A variação da resposta do calibrador com a variação do volume do frasco foi bem maior no calibrador que utiliza G-M. Ela também foi maior para 123I do que para 99mTc. CONCLUSÃO: Os resultados confirmam que a resposta dos calibradores depende do volume contido nos recipientes. Essa dependência é mais crítica para os calibradores equipados com detector G-M e para 123I quando comparado com 99mTc.

OBJECTIVE: To determine correction factors for the variation in volume of radiopharmaceuticals in containers of different geometries, comparing the influence of such factors on the determination of 99mTc and 123I activity with two types of calibrators - one with ionization chamber and another with Geiger-Müller (G-M) detector -; and to evaluate calibrators performance in the measurement of 99mTc and 123I activities. MATERIALS AND METHODS: Eight calibrators, 10R glass vials, 3 and 5 mL plastic syringes and 99mTc and 123I solutions were utilized. The correction factors were determined with basis on practical measurements of the variation in the calibrators' response according to the volume of radionuclide solution in the glass vials. The performance was evaluated according to the acceptance criterion of ±10% accuracy required by the Brazilian standard. RESULTS: The variation of the calibrators' response according to the variation in radionuclide volume was reasonably greater in the calibrator with G-M detector. It was also greater for 123I than for 99mTc. CONCLUSION: The results confirm that the calibrators' response depends on the radionuclide volume contained in the vials. Such dependence is more critical for the calibrators equipped with G-M detector and for 123I as compared with 99mTc.

Radiofarmácia e radiofármacos no Brasil: aspectos sanitários e fabris para a construção de uma linha de produção de radiofármacos PET / Radiopharmacy and radiopharmaceuticals in Brazil: sanitaries aspects related to a project of an industry of PET radiopharmaceuticals

O aumento do uso de radiofármacos PET (Pósitron Emission Tomography) vem chamando a atenção dos profissionais da área de Medicina Nuclear e Farmácia, assim como das agências reguladoras. O objetivo é prover parâmetros estruturais e legais mínimos como uma referência nacional em radiofarmácia, que possam auxiliar as agências regulatórias, focando principalmente no projeto fabril.

The increasing use of radiopharmaceuticals for PET (Positron Emission Tomography) has come to the attention of nuclear medicine staff and regulatory bodies. The aim of this study is to provide a national reference in radiopharmacy that could help all nuclear medicine staff and specially the Brazilian's regulatory bodies focused on the industrial project.